Beverage bottles are often packaged in wrap-around carriers made of paperboard sheet stock. The carriers are formed by wrapping paperboard blanks around the bottles to provide a package having two side panels foldably connected to top and bottom panels, usually leaving the ends of the carrier open. Openings in the side panels adjacent the bottom panel hold the heels or bases of the bottles in place and smaller openings in the top panel allow the necks of the bottles to protrude. A finger grip or handle in the top panel enables the user to readily lift the carrier.
The bottom panel of such carriers is normally formed from mechanically interlocked overlapping flaps which are foldably attached to the side panels. Various arrangements have been provided for locking the flaps together, one of the most popular and successful being a design which makes use of different sets of primary locking tabs and slots depending on the size of the bottles. This design takes into account the fact that all bottles of the same nominal size actually are not of exactly the same diameter, a phenomenon which tends to be even more noticeable in bottles having relatively thick foam labels.
An example of a carrier of this type is disclosed in U.S. Pat. No. 4,437,606, issued on Mar. 20, 1984 to Earl J. Graser. In the Graser arrangement two oversized position primary locking tabs located in the overlying bottom flap engage associated slots in the underlying bottom flap when the bottles are of such diameter that the girth or perimeter of the package is greater than a predetermined dimension. Two different undersized position primary locking tabs engage their associated slots when the perimeter of the package is less than the predetermined dimension. In addition, two secondary arrow-shaped punch locks connected to the underlying flap are received in associated locking openings in the overlying flap to prevent the primary locks from failing when the package is weakened through contact with water. Also, tertiary punch lock means are provided in the flaps to further strengthen the interlocking flaps and to assist in preventing the flaps from separating.
Although the Graser locking arrangement functions well, in practice it is commonly used in a carrier designed to hold six beverage bottles. While this is a popular style of carrier, there has nevertheless been a demand for packages holding only four bottles. In view of the success of the locking arrangement disclosed in Graser, bottling companies would prefer using the same design in the smaller package. This creates a number of problems.
On first glance one may think that because the package is narrower it would be sufficient to merely reduce the size of all the locking means and thereby utilize the identical locking arrangement disclosed in Graser. This approach could be thought to have some validity in view of the fact that the package would have two fewer bottles in it and therefore would have to carry less weight. In practice, however, this would not be adequate. If the locking tabs and punch locks were significantly reduced in size the areas of engagement of the tabs with their slots and the punch locks with their openings would be reduced to the point where they would be insufficient to withstand the stresses of lifting and carrying with the same margin of safety currently enjoyed in carriers designed to hold six bottles. Heavier paperboard could possibly be used to strengthen such an arrangement, but for economic reasons it would not be acceptable. If instead of reducing the size of the locking components they were retained at full size but simply squeezed closer together, the connecting portions between the tabs and punch locks would be narrowed to the point where they would become the weak link and would be in danger of tearing or yielding to lifting and carrying stresses. Again, heavier paperboard would not be a satisfactory solution.
It would therefore appear that a total redesign would be necessary, with the drawback that the features which work so well in the Graser design could not be used. It would be preferable, if the problems discussed above could be solved, to continue with the main features of the Graser design, modified to permit their use in a carrier for holding only four beverage bottles.